Production of alkyl esters from macaw palm oil by a sequential hydrolysis/esterification process using heterogeneous biocatalysts: optimization by response surface methodology

quarta-feira, fevereiro 14, 2018

The present study deals with the enzymatic
synthesis of alkyl esters with emollient properties by a
sequential hydrolysis/esterification process (hydroesterifi-
cation) using unrefined macaw palm oil from pulp seeds
(MPPO) as feedstock. Crude enzymatic extract from dormant
castor bean seeds was used as biocatalyst in the
production of free fatty acids (FFA) by hydrolysis of
MPPO.

Esterification of purified FFA with several alcohols
in heptane medium was catalyzed by immobilized Thermomyces
lanuginosus lipase (TLL) on poly-hydroxybutyrate
(PHB) particles. Under optimal experimental
conditions (mass ratio oil:buffer of 35 % m/m, reaction
temperature of 35 C, biocatalyst concentration of 6 %
m/m, and stirring speed of 1,000 rpm), complete hydrolysis
of MPPO was reached after 110 min of reaction. Maximum
ester conversion percentage of 92.4 ± 0.4 % was reached
using hexanol as acyl acceptor at 750 mM of each reactant
after 15 min of reaction. The biocatalyst retained full
activity after eight successive cycles of esterification
reaction. These results show that the proposed process is a
promising strategy for the synthesis of alkyl esters of
industrial interest from macaw palm oil, an attractive
option for the Brazilian oleochemical industry.